The thriller tells the story of police detective Ja-seong (Lee Jung-jae), who is assigned by his boss Park (Choi Min-sik) to do an undercover investigation into “Gold Moon,” one of the biggest crime organizations in the country. Ja-seong disguises himself as one of the gang’s members.

A scene from upcoming film “New World” (NEW)

The investigation goes on for eight years, and Ja-seong finds himself caught between the gang’s second-in-command Jeong Cheong (Hwang Jeong-min), who “trusts him with his life,” and his senior detective Park, who uses Ja-seong for his own success. The film deals with the themes of betrayal and loyalty, as well as conspiracy.

Park was one of the writers for Kim Ji-woon’s 2010 film “I Saw the Devil,” which starred Choi Min-sik as a serial killer.

The two met during the production phase of the film, and Park told Choi about some of the scripts he was working on at the time, including the “New World.” Choi was impressed and promised to star in the films.

“I felt like this guy had something,” Choi said through the promoters. “All of the scripts sounded interesting. But it seemed like ‘New World’ would attract the investors the most.”

It was also Choi who brought actor Lee Jung-jae into the project.

“It was actually Choi who called me and asked me to read over the script,” said Lee. “He sounded almost as if he were producing this film. Of course, I was really excited to work with someone as great as Choi.”

Meanwhile, Hwang had to learn Chinese for his role as Jeong Cheong, who is a descendent of Chinese migrants who settled in Korea’s Jeolla provinces.

“The role required me to speak in Chinese for a number of scenes,” Jeong said. “Learning Chinese was certainly more challenging than mastering the Jeolla accent.”